Bats Carry Corona Virus. So Why Don’t They Get Sick?
A lot of viruses that has taken a toll on life, the ebola virus in Africa, The Nipah virus of Nipah and the most recent one corona virus that left china running helter skelter all seemed to have originated from bats. During the course of the virus epidemic in Wuhan where it was first detected, some Chinese researchers in Wuhan examined some patients affected in that area and then took samples of the virus.
They did findings on the genetic sequence of the virus with other viruses that were known. The corona virus surprisingly had a 96% match with the horseshoe bats that are dominant in the southwest of china. The research findings were then published in a study on February, 2020.
A virologist Vineet Menachery from the university of Texas Medical Branch at Galveston though not affiliated to the study said “They’re too close in terms of their pure genetics to say they’re not related, or that they didn’t have a common ancestor.”
Menachery was a reputable virologist and had done other research works. He contributed to the theory that the spread of the corona virus must have been from these bats to humans. And possibly must have had another animal that served as an intermediary for the spread.
This same thing had happened with other forms of corona viruses as noted in the case of SARS (Severe Acute Respiratory Syndrome) an outbreak that took place in 2002-2003 where civets, a mongoose family member were infected with the bat corona virus and spread as humans bought them for food.
Another case was the MERS (Middle East Respiratory Syndrome) outbreak. This one happened in 2012 and was as a result of infected camels from the virus. People who ate undercooked meat of camels and as well drank the raw milk of camels were all affected.
So why is it that there are so many diseases that are spread from bats?
Its no doubt, bats have a lot of viruses that they carry with them. And these viruses in their variety are spread and manifests its tolls on people. Scientist are not sure why this is the case as confirmed by Kevin Olival, a research vice president as EcoHealth Alliance, a non-profit organization based in the U.S. He went further to say that it may have something to do with the family of the viruses carried by the bats. So you know, there are over 130 different families of viruses that bats do carry around.
And then, most bats and humans do come in contact through several means. The millions of populations of bats are ubiquitous to all the continents apart from in antartica. Rebekah of Colorado State university who researched infectious pathogens said “There’s a lot of viruses we’re finding in bats because there’s a lot of bats out there.”
They move about in multitudes and live in colonies of large populations. Some these members live in caves and share caves and trees where there can be a contact between humans and bats. Hence, these viruses can spread from these bats to humans.
Despite their sizes, bats have relatively long lifespans and can live over 30 years.”So there’s a long time for them to be persistently infected with the virus and shed it into the environment,” Kading says. The mode of mechanisms for these viruses are through urine, saliva and feces of bats. The outbreak of Nivah that happened in Bangladesh was linked to the sap of a date palm gotten from some trees that some bats licked and had infested with their urine.
Reading through all these, it is not absurd to wonder why the bats themselves do not get affected by the viruses they carry.
The answer to that question is based on the fact that the bat is the only flying mammal in the world. Their body metabolism and process quite differ from that of normal mammals too. When bats fly, their heart rates rise to about a thousand beats per minute with a temperature rise of about 100 degrees Fahrenheit. Linfa Wang a student of bat viruses at Duke-NUS Medical School in Singapore says that when these signs manifest in other mammals, they are signals that can trigger death. But this is not the same case for other bats. This is a lifestyle for them, every day.
Their system is also capable of producing molecules that other organisms do not have. The molecules carry out repair functions and prevent cell damage. This makes their system a bit irresistible to infections and also make them recalcitrant to viruses and resilient to diseases such as diabetes, cancer and other health conditions.
This is a prove that the manifestation of viruses in mammals is not always as a result of the virus itself, but as a result of the body’s reaction to the presence of such a virus that makes us ill by triggering other chain reactions, as Wang explains.
Olival at EcoHealth explains that these bats have coevolved with these viruses and it is not totally their fault that we humans are infected and affected by these viruses. The actual problem is when the viruses move from their species to other species of mammals which is also fostered by human activity.
Naturally, it would be hard for most animals and mammals to cross paths. But Olivial says that the presence of some activities and availability of exchange platforms made available by humans can allow such interaction to occur. She gave an example using wildlife markets like the one in Wuhan, where a bat could be mixed up with a civet. Who later on come in contact with humans – eg. Butchers who do not observe proper hygiene and protection from animal blood.
“The way that we’re coming into contact with these animals, hunting, selling, and trading them is to a scale that really we haven’t seen before,” he says.
Investigative teams did some in-depth search and they discovered some traces of this virus in 22 stalls and in a garbage truck that was found at Huanan Seafood Market right there in Wuhan, a place known for booming trade for live animals. This discovery led to shutting down the market as it was tied to majority of the cases.
The intermediary animals to this viruses are still a mystery, but it is clear that some of these animals are prone to interact more with humans. This is why when they are infected, the likelihood for human infection is widened. These other infected animals can sneeze, urinate, be cooked as food or even owned as pets.
Bats are not just vectors for viruses, they play an important role in balancing the eco-system. They feed on insects and fruits and are active agents of pollination. In fact, Wang believes that since these bats have successfully coevolved with these viruses, there is every possibility that they can be the agents that can lead to the cure and provision of therapies for these viruses.